1. Field of the Invention
The present invention relates to a high voltage multi-layer ceramic capacitor (MLCC) that may enable a surface mounting, and may form a guide electrode between inner electrodes or between sealing electrodes to thereby prevent a decrease in an inner voltage, caused by a parasitic capacitance, and a director current (DC) link capacitor module using the MLCC.
2. Description of the Related Art
An electric power transfer device of an electric vehicle or a hybrid vehicle that uses an electric drive source includes a battery, a capacitor module, an inverter, and a motor.
The electric power transfer unit constructed as above will be described with reference to FIG. 1.
A shown in FIG. 1, the electric power transfer unit of the electric vehicle or the hybrid vehicle may include a battery 1, a capacitor module 2, an inverter 3, and a motor 4.
The battery 1 may be used as a power source and the motor 4 may be used as a drive source. In order to control a driving speed and a torque of the motor 4, the inverter 3 may receive a pulse width modulation (PWM) duty signal from a micro processing unit (MCU) (not shown). The inverter 3 may be switched according to the received PWM duty signal to thereby convert a direct current (DC) power output from the battery 1, and may apply the DC power to the motor 4 to drive the vehicle.
The capacitor module 2 may smooth and stabilize the DC power supplied from the inverter 2, and decrease a current ripple to stably supply the DC power to the inverter 3. The capacitor module 2 stably supplying the DC power to the inverter 3 may be connected with a plurality of DC-link capacitors C1, C2, C3, and C4 in parallel. A high voltage multi-layer ceramic capacitor (MLCC) may be used for each of the capacitors C1, C2, C3, and C4. The horizontal length and the vertical length of the capacitors C1, C2, C3, and C4 are being enlarged to be used for a high voltage field. When providing external electrodes 2b of FIG. 2 in both ends of the enlarged capacitors C1, C2, C3, and C4, a conventional dipping scheme may be inapplicable.
When forming external electrodes 2a in both ends of the enlarged capacitor C1 by applying the dipping scheme as shown in FIG. 2, the external electrodes 2a may not be formed up to the surface of a ceramic laminated layer 2a. When the external electrode 2a is unstably formed, the capacitor 1 may not tightly contact with a printed circuit board (not shown) in manufacturing the capacitor module 2. Accordingly, due to a vibration, an impact, and the like occurring while driving a vehicle, a contact error may incur in the capacitor 1. In order to enhance the above shortage, a lead terminal (not shown) is used as the external electrode 2b in the conventional art.
When a lead terminal is used for a high voltage multi-layer ceramic capacitor (MLCC) used as a conventional direct current (DC) link, the lead terminal is inserted into a printed circuit board in manufacturing a capacitor module, which makes a mounting operation difficult.